In recent years, an audio and a video product, an air-conditioner and other various electronic products are gaining higher functions. In this trend, a switching device and a remote control unit which can be used for diversified operations and are produced in a compact size are demanded.
A conventional switching device is explained using FIG. 4.
FIG. 4 is a perspective view of the conventional switching device. A plurality of wiring patterns is formed (not shown) on at least one of a main side and an other main side of wiring substrate 1 as shown in the drawing. Operating part 2 is placed on one of the main side and the other side of wiring substrate 1 in a rotatable manner. The operating part is substantially in a disk shape. A plurality of cams 3, 3A and 3B are formed at a lower outer periphery of operating part 2. The cams extrude outward and are formed with a certain distance between each cam.
Switch 4 includes lever 5 which extrudes from case 6 made of insulating resin. Lever 5 can be rock-motioned. When lever 5 is rock-motioned in right or left direction that is in R4 or L4 direction, a moving contact piece (not shown) accommodated in case 6 is connected to or disconnected from a plurality of fixed contact pieces (not shown) in switch 4. An electric signal switched by switch 4 is output from a plurality of terminals 7
Switch 4 is so called a ‘return-to-neutral’ type. When an operational force applied to lever 4 is removed after rocking the lever in right or left direction namely in R1 or L1 direction, the lever automatically returns to an original neutral position with a resilient force of a spring (not shown) accommodated in case 6.
Switch 4 is placed at an outside part of the outer periphery of operating part 2 mounted on one of the main sides so as lever 5 to be engaged with cams 3, 3A or 3B of operating part 2. Terminals 7 are soldered to predetermined spots of the wiring pattern and are connected to a controller (not shown) that is composed of a microprocessor and other electronic components, constituting the switching device.
The conventional switching device constituted in this manner is installed in an electronic product or in a remote control unit with operating part 2 protruding from an operational part of the electronic product or the control unit, and the wiring pattern of wiring substrate 1 is electrically connected to an electronic circuit of the product or the remote control unit through a connector or the like.
In above constitution, when operating part 2 is rotated in clockwise or counter-clockwise direction, cam 3A or cam 3B of operating part 17 comes into contact with lever 5 of switch 4 with rotational movement of the operating part, rocking lever 5 in left or right or in L4 or R4 direction, making an electrical connection or disconnection of the moving contact piece with the fixed contact piece.
As an example, when operating part 2 is largely rotated in counter-clockwise direction, cam 3B first pushes lever 5 of switch 4 rocking the lever in R4 direction. The lever once automatically returns to the original neutral position, and then pushed by cam 3C and rocked again in R4 direction, making two times of electrical connection and disconnection.
The electric signals caused by the electrical connections and disconnections are output through a plurality of terminals 7 to the controller. As lever 5 is rocked in R4 or L4 direction by certain times, the controller detects the rotational direction and an angle of operating part 2 corresponding to times of electrical connection and disconnection, recognizing a moved position of operating part 2.
Thus, with the rotational movement of operating part 2, audio volume, channel selection of TV, temperature of air-conditioner and other switching activities can be controlled.
As prior technical information on the applied invention, Japanese Patent Unexamined Publication No. 2003-132765 is available.
In the conventional switching device, however, switch 4 is disposed at an outside part of an outer periphery of operating part 2, and lever 5 is pushed by the moving force of cams 3, 3A, 3B and 3C extruding from operating part 2, so a large space is taken on wiring substrate 1, making a high-density components mounting difficult.